Spatial distribution of total petroleum hydrocarbons in sediments of Pulicat Lake, Southeast coast of India

Abstract

Semi-enclosed coastal environments are under constant stress due to diverse chemical pollutants from multiple anthropogenic sources. Among them, total petroleum hydrocarbons (TPHs) are most common in coastal environments. Pulicat Lake is one such environment situated on the southeast coast of India where, the present study was conducted. The TPHs were measured using a modified ultrasonication method, so as to reduce the organic solvent consumption as well as to minimize time. The TPHs in Pulicat Lake sediments ranged from 0.28 to 6.86 μg/g dry weight with a median of 0.71 ± 1.59 μg/g dry weight. Euclidean based cluster analysis using normalized data of TPHs, SOC and sediment texture classified the lake into three discrete regions such as south, central and north. Linear regression analysis showed positive correlation of TPHs with SOC (R2 = 0.567, P < 0.02), mud (silt+clay) (R2 = 0.514, P < 0.05) and negative with sand (R2 = 0.519, P < 0.05). The TPH concentrations observed in Pulicat Lake during the study period pose less ecological risk to the environment and biota.

Keywords

• TPH
• Ultrasonication
• Sediments
• SOC
• Texture
• Ecological risk status